Kinasiatit

Kinasiatit is a rare silicate mineral that belongs to the orthorhombic crystal system. Its chemical formula is commonly cited as KFe2(Si4O10)(OH)4, indicating the presence of potassium, iron, silicon, oxygen, and hydroxyl groups. The mineral typically forms prismatic crystals with a pale green to yellowish color that becomes darker when exposed to light or air. It displays a Mohs hardness of 4 to 5 and has a specific gravity ranging from 3.1 to 3.3. The surface of kinasiatit is often sub‑conchoidal to subconchoidal, and it exhibits a vitreous luster. In many cases, the crystals are intergrown with chlorite or a small amount of phyllite, making identification through visual inspection alone somewhat challenging.

The mineral was first described in the early 20th century from an altered iron‑rich ultramafic mass near Karatau, Kazakhstan. Since that time, similar specimens have been documented in the Lunigiana limestone region in Italy and in the Ponce de León basaltic flows of the Canary Islands. Kinasiatit usually occurs in metamorphosed limestone or in the alteration zones of greenschist facies metamorphism. Its formation is associated with fluid‐rich, low‐grade metamorphic conditions where potassium and iron can substitute into the silicate lattice. The mineral is most frequently found as a secondary product of the weathering of more common orthosilicates.

Although kinasiatit is not widely reported as an ore mineral, it is of interest to mineralogists because of its unique composition that bridges characteristics of both orthosilicates and alkali feldspars. It has occasionally been used as a check stone in gemology because of its distinct cleavage and brittleness, but it has not been employed in industrial processes. Current databases such as Webmineral and the Handbook of Mineralogy list kinasiatit in a few entries, and recent studies suggest its crystal chemistry provides insight into the behavior of potassium in low‑temperature metamorphic environments.